Scientists of various specialties and backgrounds have been brought together in order to study basic elements within human communication. Previously, they have concentrated their efforts on the speech production/reception paradigm. The focus of this proposal, however, is one that is exclusively directed to the study of laryngeal function and voice production. Our approach is as follows. Each of the investigators brings his particular skills and orientation to the specific problem; in small groups, they focus on programmatic level issues designed to further the state-of-the-art with respect to one or more of the areas of voice study included in this proposal. Several dimensions or levels are attacked. The first level concerns the specification and refinement of theory; the development of models of voice production. On a second level, efforts are made to generate data that leads to the development of newer models and to the testing of theory. The efforts with respect to the third dimension, focus on practical or applied issues. In this case, the thrust of the research is toward acquisition of information that will provide practical data for individuals (such as clinicians) who are attempting to modify the vocal output of humans. Progress to date demonstrates that the interdisciplinary amalgamation of the talents and skills of diversely trained specialists is possible providing they have interest in common goals--those that transcend their specific orientation. Indeed, this blending of talents has proved to be productive of substantial information with respect to the speech production-reception paradigm; it should continue to be so relative to the proposed research on laryngeal function and voice production. The specific thrust of the proposed research is directed at the human voice on a global basis. However, the total program is broken up into a variety of new and restructured projects. Included are the (computer) implementation and testing of models of voice production, the development and testing of a model of vocal registers, the testing of an age/sex speaking fundamental frequency model, a new program designed to identify differences between the voices of singers and non-singers, several programs that should lead to the early detection and prevention of voice disorders, research on voice physiology and so on.